import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

//读取数字
public class SortMapper extends Mapper<LongWritable, Text, IntWritable, NullWritable> {
    /*
     1.读取文本内容，转为int类型
     2.输出<数字，null>
    */
    final IntWritable num = new IntWritable();
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        num.set(Integer.parseInt(value.toString()));
        context.write(num,NullWritable.get());
    }
}
